From 74ebd2ba1ef649a9c4abe3937c2d4d9767484a54 Mon Sep 17 00:00:00 2001
From: Jan Varga <jan.varga@gmail.com>
Date: Tue, 25 Sep 2018 11:53:39 +0200
Subject: [PATCH] Bug 1492737 - Part 1: Support passing name length to
 JS_GetOwnUCPropertyDescriptor and add JS_GetUCPropertyDescriptor; r=Waldo

---
 dom/xbl/nsXBLBinding.cpp   |  3 ++-
 dom/xbl/nsXBLProtoImpl.cpp | 13 +++++++++----
 js/src/jsapi.cpp           | 18 +++++++++++++++---
 js/src/jsapi.h             |  6 +++++-
 4 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/dom/xbl/nsXBLBinding.cpp b/dom/xbl/nsXBLBinding.cpp
index aa72a9f6d1a2..1ea06b9419ca 100644
--- a/dom/xbl/nsXBLBinding.cpp
+++ b/dom/xbl/nsXBLBinding.cpp
@@ -984,7 +984,8 @@ nsXBLBinding::DoInitJSClass(JSContext *cx,
   // to create and define it.
   JS::Rooted<JSObject*> proto(cx);
   JS::Rooted<JS::PropertyDescriptor> desc(cx);
-  if (!JS_GetOwnUCPropertyDescriptor(cx, holder, aClassName.get(), &desc)) {
+  if (!JS_GetOwnUCPropertyDescriptor(cx, holder, aClassName.get(),
+                                     aClassName.Length(), &desc)) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
   *aNew = !desc.object();
diff --git a/dom/xbl/nsXBLProtoImpl.cpp b/dom/xbl/nsXBLProtoImpl.cpp
index 2b996b4616c1..2b24390b9475 100644
--- a/dom/xbl/nsXBLProtoImpl.cpp
+++ b/dom/xbl/nsXBLProtoImpl.cpp
@@ -96,11 +96,15 @@ nsXBLProtoImpl::InstallImplementation(nsXBLPrototypeBinding* aPrototypeBinding,
   // end up with a different content prototype, but we'll already have a property
   // holder called |foo| in the XBL scope. Check for that to avoid wasteful and
   // weird property holder duplication.
-  const char16_t* className = aPrototypeBinding->ClassName().get();
+  const nsString& className = aPrototypeBinding->ClassName();
+  const char16_t* classNameChars = className.get();
+  const size_t classNameLen = className.Length();
+
   JS::Rooted<JSObject*> propertyHolder(cx);
   JS::Rooted<JS::PropertyDescriptor> existingHolder(cx);
   if (scopeObject != globalObject &&
-      !JS_GetOwnUCPropertyDescriptor(cx, scopeObject, className, &existingHolder)) {
+      !JS_GetOwnUCPropertyDescriptor(cx, scopeObject, classNameChars,
+                                     classNameLen, &existingHolder)) {
     return NS_ERROR_FAILURE;
   }
   bool propertyHolderIsNew = !existingHolder.object() || !existingHolder.value().isObject();
@@ -115,8 +119,9 @@ nsXBLProtoImpl::InstallImplementation(nsXBLPrototypeBinding* aPrototypeBinding,
 
     // Define it as a property on the scopeObject, using the same name used on
     // the content side.
-    bool ok = JS_DefineUCProperty(cx, scopeObject, className, -1, propertyHolder,
-                                  JSPROP_PERMANENT | JSPROP_READONLY);
+    bool ok =
+      JS_DefineUCProperty(cx, scopeObject, classNameChars, classNameLen,
+                          propertyHolder, JSPROP_PERMANENT | JSPROP_READONLY);
     NS_ENSURE_TRUE(ok, NS_ERROR_UNEXPECTED);
   } else {
     propertyHolder = targetClassObject;
diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index 1f0dfe5416b8..79008dd11435 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -2077,10 +2077,10 @@ JS_GetOwnPropertyDescriptor(JSContext* cx, HandleObject obj, const char* name,
 }
 
 JS_PUBLIC_API(bool)
-JS_GetOwnUCPropertyDescriptor(JSContext* cx, HandleObject obj, const char16_t* name,
+JS_GetOwnUCPropertyDescriptor(JSContext* cx, HandleObject obj, const char16_t* name, size_t namelen,
                               MutableHandle<PropertyDescriptor> desc)
 {
-    JSAtom* atom = AtomizeChars(cx, name, js_strlen(name));
+    JSAtom* atom = AtomizeChars(cx, name, namelen);
     if (!atom) {
         return false;
     }
@@ -2105,7 +2105,19 @@ JS_GetPropertyDescriptor(JSContext* cx, HandleObject obj, const char* name,
         return false;
     }
     RootedId id(cx, AtomToId(atom));
-    return atom && JS_GetPropertyDescriptorById(cx, obj, id, desc);
+    return JS_GetPropertyDescriptorById(cx, obj, id, desc);
+}
+
+JS_PUBLIC_API(bool)
+JS_GetUCPropertyDescriptor(JSContext* cx, HandleObject obj, const char16_t* name, size_t namelen,
+                           MutableHandle<PropertyDescriptor> desc)
+{
+    JSAtom* atom = AtomizeChars(cx, name, namelen);
+    if (!atom) {
+        return false;
+    }
+    RootedId id(cx, AtomToId(atom));
+    return JS_GetPropertyDescriptorById(cx, obj, id, desc);
 }
 
 static bool
diff --git a/js/src/jsapi.h b/js/src/jsapi.h
index 8cbe17f8d335..fd746d70470f 100644
--- a/js/src/jsapi.h
+++ b/js/src/jsapi.h
@@ -2183,7 +2183,7 @@ JS_GetOwnPropertyDescriptor(JSContext* cx, JS::HandleObject obj, const char* nam
                             JS::MutableHandle<JS::PropertyDescriptor> desc);
 
 extern JS_PUBLIC_API(bool)
-JS_GetOwnUCPropertyDescriptor(JSContext* cx, JS::HandleObject obj, const char16_t* name,
+JS_GetOwnUCPropertyDescriptor(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
                               JS::MutableHandle<JS::PropertyDescriptor> desc);
 
 /**
@@ -2200,6 +2200,10 @@ extern JS_PUBLIC_API(bool)
 JS_GetPropertyDescriptor(JSContext* cx, JS::HandleObject obj, const char* name,
                          JS::MutableHandle<JS::PropertyDescriptor> desc);
 
+extern JS_PUBLIC_API(bool)
+JS_GetUCPropertyDescriptor(JSContext* cx, JS::HandleObject obj, const char16_t* name, size_t namelen,
+                           JS::MutableHandle<JS::PropertyDescriptor> desc);
+
 /**
  * Define a property on obj.
  *